we are asked for a sure conclusion from the passage.
We do not know wheather body can produce something else(other than antibody) to fight the virus,say, 2 years after the body is infected.
But, we can be sure of E, because "after a week, body produce antibody" and"there is now a test" that can tell how many antibody there.
So, by antibody test, there will be at least couple of days(within a week),no exhibition of infection is detected.
am I right?
[em14]
[此贴子已经被作者于2002-9-24 2:24:39编辑过] |